function showDialog(htmlContent, box_width, box_height, textTitle)
{
	var box_width2 = box_width + "px";
	var box_height2 = box_height + "px";
	var marginleft = -(box_width/2) + "px";
	var margintop = -(box_height/2) + "px";
	
	var titleHtml = '';
	if(typeof textTitle != 'undefined')
	{
		titleHtml = '<div class="title-bar top_right_radius">' + textTitle + '</div>';
	}

	$("#dialog_bg").remove();

	//定义弹出层的DIV
	var dialogHtml = '<div id="dialog_bg"></div><div id="dialog_box"><div id="dialog_close">&nbsp;</div>' + titleHtml + 
				     '<div id="dialog_content">' + htmlContent + '</div></div>';

	$("body").append(dialogHtml);

	//定义外层BOX的宽度和位置，用于屏幕居中显示
	$("#dialog_box").css({width:box_width2,height:box_height2,"margin-left":marginleft,"margin-top":margintop});
	//点击关闭按纽时移除弹出层
	$("#dialog_close").click(function(){
		$("#dialog_bg").remove();
		$("#dialog_box").remove();
	});
}